Journal of Climate Change and Pollution

ABSTRACT

Biochar from waste and biomass has been gaining attention in soil fertility improvement and nature-based solutions to mitigate climatic changes. This study presents a meta-analysis examining biochar’s contribution in improving soil health and promoting nature-based solutions (NbS). Biochar, a carbon-rich product derived from pyrolysis of organic biomass, has been widely investigated for its capacity to store carbon, boost crop yields, and enhance soil health. Despite the rapid expansion of research, individual studies report varying results depending on soil types, climatic conditions, feedstock, and pyrolysis processes. To address these inconsistencies, this meta-analysis synthesizes findings from over 600 peer-reviewed studies and recent global meta-analyses. The findings show that the use of biochar greatly improves soil organic carbon, nutrient retention, and crop productivity especially in low-fertility tropical soils and under moderate pyrolysis temperatures. Furthermore, biochar enhances carbon sequestration efficiency, reduces nitrous oxide emissions in certain contexts, and supports degraded land restoration, thereby aligning with NbS principles. However, outcomes remain context-dependent, with microbial diversity responses and long-term ecological trade-offs requiring further study. The findings highlight biochar’s potential as a sustainable soil management strategy and climate mitigation tool, while emphasizing the need for site-specific recommendations, integration with other NbS practices, and supportive policies for large-scale adoption.

Keywords: Biochar; Soil; Climate; Nature-based Solutions; Large-Scale Adoption